Production and treatment of artificial textile materials containing organic derivatives of cellulose



Patented Apr. 25, 1939 UNITED STATES PRODUCTION AND TREATMENT OF ARTIFI- CIAL TEXTILE MATERIALS CONTAINING ORGANIC DERIVATIVES OF CELLULOSE Henry Dreyfus, London, England No Drawing. Application February 4, 1936, Se-

rial No. 62,329. 1935 '7 Claims.

This invention relates to improvements in the production and treatment of artificial materials, and particularly to improvements in processes wherein artificial filaments, yarns and similar textile materials containing organic derivatives of cellulose are stretched.

It is known that by stretching artificial filaments and similar materials having a basis of organic derivatives of cellulose their physical prop- 1 erties, and particularly their tensile strength, may be improved. It is possible, however, to stretch artificial filaments, yarns and similar textile materials by only a relatively small extent, for example about 20 to 25%, when they are in a finished condition, and in order that a higher degree of stretching may be achieved, it is in general necessary to bring the materials to a softened condition, for example by treatment with volatile solvents.

It has now been discovered that when artificial filaments, yarns and similar textile materials of organic derivatives of cellulose contain plasticisers of high compatibility they can be stretched to an exceptional extent without the necessity for treating them with softening media, and according tothe present invention, therefore, artificial filaments, yarns and similar textile materials having a basis of organic derivatives of cellulose and containing plasticisers for such cellulose derivatives which are compatible therewith in high proportions, are subjected to a stretching operation.

The invention is of particular importance in connection with the manufacture of artificial filaments, yarns and similar textile materials having a basis of cellulose acetate, but it is also applicable generally to the manufacture of artificial textile materials having a basis of other organic derivatives of cellulose, for example cellulose formate, cellulose propionate, cellulose butyrate, cellulose nitro-actetate and other cellulose esters and mixed esters, methyl cellulose, ethyl cellulose, butyl cellulose and other cellulose ethers and mixed ethers, and cellulose ether-esters, e. g. ethyl cellulose acetate and oxyethyl cellulose acetate.

As stated above the plasticisers employed according to the present invention are compatible with the cellulose derivatives in high proportions, e. g. 50-70% or more. It is preferable that the plasticisers should be compatible in proportions of 100% or more on the weight of the cellulose derivative. Suitable plasticisers are. tartrate esters, e. g. dibutyl tartrate and diamyl tartrate, phthalate esters, e. g. dimethyl phthalate, diethyl phthalate, dimethyl glycol phthalate, diethyl glycol phthalate, and dibutyl glycol phthalate, triethyl citrate, cresyl glyceryl diacetate, methyl cyclohexanyl oxalate, benzyl benzoate, triacetin, triphenyl-acetin, aromatic sulphonamides and In Great Britain March 7,

alkyl substitution derivatives thereof, e. g. para- I toluene sulphonamide and the isomeric xylene sulphonamides, and benzyl alcohol.

The plasticisers may be incorporated in the artificial textile materials by introducing them into the spinning solutions and forming the solutions into the artificial textile materials by dry spinning processes. Wet spinning processes may also, if desired, be employed. When textile materials are formed by wet spinning processes from solutions containing plasticisers, the coagulating conditions should be such that a substantial proportion of plasticiser remains in the materials after they have been withdrawn from the coagulating bath.

The plasticisers are preferably present in the materiais to be stretched in substantial proportions, e. g. in proportions of 40-60% up to 80- 100% or more, based on the weight of the cellulose derivative. 7

Artificial filaments, yarns and similar textile materials may be stretched in the formof hanks or other packages, but preferably stretching is effected during the course of their travel from one point to another, for example during their transfer from one bobbin to another. It is of particular advantage to stretch a plurality of yarns simultaneously whilst they are spaced apart in parallel alignment and substantially in sheet formation, by means of devices stretching across the entire sheet. Again, artificial filaments and like materials may be stretched during their travel from spinning machines in which they have been produced to suitable winding devices. The stretching may be efiected in a single stage or in two or more stages with or without intermediate stages during which the materials are released from the stretching tension.

Stretching of the materials may be effected at normal temperatures, particularly if they contain high proportions of plasticisers. Preferably, however, particularly if high degrees of stretch are to be eifected, e. g. stretches of 200%, 400% or more of the original length of the materials, the stretching operation is carried out at increased temperatures, for example by passing the materials through a vessel containing a suitable gas or vapour, e. g. wet or dry steam or air under normal or superatmospheric pressure, or a suitable liquid, e. g. hot Water, such gas, vapour or liquid being maintained at a suitable temperature, e. g. 50 to 100 C. or 120 C. or above. Artificial filaments and the like may be stretched to a comparatively small extent, e. g. to 150 or 200% of their original length, or, if desired, considerably higher stretches may be effected, for exampie to 400 or 600% or more of their original length.

The plasticisers or a proportion thereof may be removed from the filaments or other textile materials during or after the stretching operation. Thus the stretching may be effected at high temperatures by passing the textile materials containing the plasticisers through hot liquids which are solvents for the plasticiser and thus remove it from the materials during the stretching operation. The plasticisers may be wholly or partly removed from the materials after the stretching operation by any suitable method, e. g. by treating the materials with a liquid which is 'a solvent for the plasticiser employed and is a non-solvent for the organic derivatives of cellulose. Examples of suitable liquids are hydrocarbons and chlorinated hydrocarbons, e. g. benzene, toluene, dichlorethylene, and carbon tetrachloride, ethers, e. g. diethyl ether and di-isopropyl ether, and alcohols, e. g. methyl alcohol and ethyl alcohol. Water or aqueous solutions of suitable liquids, e. g. aqueous solutions of alcohols, may also be. employed.

The following examples illustrate the invention but are not to be regarded as limiting it in any way:

Example 1 Filaments of cellulose acetate are formed by dry spinning a solution of cellulose acetate containing (SO-70% on the weight of the cellulose acetate of para-toluene, sulphonamide. Such filaments, during their travel from the spinning chamber to a'winding device, are passed through a chamber containing wet steam at superatmospheric pressure, and are simultaneously stretched. The plasticizer in the materials is subsequently removed, at least in part, by treatment of the materials with ethyl alcohol.

Having described my invention what I desire to secure by Letters Patent is:

1. Process for the manufacture of artificial textile materials of improved properties, which comprises stretching at temperatures of at least 50 C. artificial filaments, yarns and like textile materials having a basis of an organic derivative of cellulose, containing a proportion of at least 40% on the weight of the cellulose derivative of a plasticizer for such cellulose derivative which is compatible therewith in a proportion of at least. 50%and containing substantially no volatile softening agent.

2. Process for the manufacture of artificial textile materials of improved properties,'which comprises forming artificial filaments, yarns and like textile materials having a basis of an organic derivative of cellulose and containing at least 40%oftheir weight of a plasticizer for the organic derivative of cellulose which is compatible therewith in a proportion of at least 70% by an evaporative process from a spinning solution containing the organic derivative of cellulose and the plasticizer, and then stretching the materials at a temperature of at least 50 C. to at'least 150% of their original length during their travel from one point to another while they are substantially free from volatile softening agent.

3. Process for the manufacture of artificial textile materials of improved properties, which comprises stretching at temperatures of at least 50 C. during their travel from one point to another artificial filaments, yarns and like textile materials having a basis of an organic derivative of cellulose, containing a proportion of at least 40% on the weight of the cellulose derivative of a plasticizer for such cellulose derivative which is compatible therewith in a proportion" of at least 70% of the weight of the cellulose derivative and containing substantially no volatile softening agent.

4. Process for the manufacture of artificial textile materials of improved properties, which comprises stretching to at least 150% of their original length and during their travel from one point. to another at temperatures of at least 50 C. artificial filaments, yarns and like textile materials having a basis of cellulose acetate, containing a proportion of at least 60% on the weight of the cellulose acetate of a plasticizer for the cellulose acetate which is compatible therewith in a proportion of at least 70% and containing substantially no volatile softening agent.

5'. Process for the manufacture of artificial textile materials of improved properties, which comprises stretching at temperatures of at least 90 C. during their travel from one point to another artificial filaments, yarns and like textile materials having a basis of cellulose acetate, containing a proportion of at least 40% on the weight of the cellulose acetate of a plasticizer for the cellulose acetate which is compatible therewith in a proportion of at least 50% and containing substantially no volatile softening agent.

6. Process for the manufacture of artificial textile materials of improved properties, which comprises stretching to at least 200% of their original length and during their travel from one point to another at temperatures of at least 90 C. artificial filaments, yarns and like textile materials having a basis of cellulose acetate, con-' taining a proportion of at least 60% on the weight of the cellulose acetate of a plasticizer for the cellulose acetate which is compatible therewith in a proportion of at least 100% and containing substantially no volatile softening agent.

7. Process for the manufacture of artificial textile materials of improved properties, which comprises forming artificial filaments, yarns and like textile materialsv having a basis of cellulose acetate and containing at least 60% of their Weight of a plasticizer for the cellulose acetate which is compatible therewith in a proportion of at least 100% by an evaporative process from a spinning. solution containing the cellulose acetate and the plasticizer, and then stretching said materials to at least 200% of their original length during their travel from one point to another at a temperature of. at least 90 C. while they are substantially freefrom volatile softening agent.

HENRY DREYFUS. 

